In the movement of cards within playing card-handling devices, a typical card-feeding system may include pick-off roller(s) that are located on the bottom of stacks to remove one card at a time. The weight of a stack of cards ordinarily provides sufficient traction against the rollers to assure proper movement of most of the cards. But as the stack thins out after most of the cards have been delivered, the weight may no longer be sufficient (especially with the last few remaining cards in the stack) to assure proper movement of the cards.
U.S. Pat. No. 5,692,748 (Frisco) describes a card-shuffling device containing free-swinging weights on pivoting arms to apply pressure to the top of stacks of cards that are to be mixed. The disclosure, particularly that relating to FIGS. 4b-4d, states: “To assure traction between the wheels 48a, b, the circumference thereof has a coefficient friction to engage and pull a card, transport it and ejected it from the respective chutes 44a, b into the shaft 24. While preferably pairs of wheels 48a, b are used, it is to be understood that a single wheel or a cylinder could also be used as the tractive element. To impose a load on cards 30 deposited in the first and second chambers 34, 36 to assure traction with the wheels 48a, b, means are provided to vertically load the cards and urge them against the floors 40. For this purpose, each of the first and second chambers 34, 36 has an arm 52 pivotly mounted at one end by a pivot 54 to the housing 12 and having at the other end a foot 56. As described hereinafter, when cards are cut and deposited into the first and second chambers 34, 36, the arms 52 pivot as the cards 30 are urged over the front barriers 42 into their nested positions in the first and second chambers 34, 36. As nested on the floors 40 of the first and second chambers 34, 36, the arms remain in contact with the top of the cards 30 to impose a vertical load on the cards 30 to urge them to be contacted by the wheels 48a, b. Proximate the foot 56 of each arm 52, a weight 58 is provided on each of the arms 52. While a single arm 52 is shown it is to be understood that a pair of such arms 52 could be used at each of the chambers.” These weights on pivoting arms apply pressure through the stack(s) of cards to assure traction against a pick-off roller at the bottom of the stack. This shows a pivoting weighted arm over the card infeed portions of a playing card shuffler.
U.S. Pat. Nos. 6,655,684; 6,588,751; 6,588,750; 6,568,678; 6,325,373; 6,254,096; 6,149,154; (Grauzer) and U.S. Pat. Nos. 6,139,014; 6,068,258; 5,695,189 (Breeding) describe a shuffler or card delivery shoe having a standard free-floating weight to provide increased force on the cards to keep them oriented and assist in their advancing. The Breeding references disclose sensors for detecting the presence of cards in a delivery tray or elsewhere.
U.S. Pat. No. 6,637,622 (Robinson) describes a card delivery device with a weighted roller assisting in allowing the cards to be easily removed. The weighted cover is on the delivery end of the dealing shoe, covering the next card to be delivered.
U.S. Pat. No. 5,722,893 (Hill) describes the use of a weighted block behind cards in a delivery shoe to provide additional weight on the cards to trigger sensors. The reference specifically states: “In operation, a wedge-shaped block mounted on a heavy stainless steel roller (not shown) in a first position indicates that no cards are in the shoe. When the cards are placed in the shoe, the wedge-shaped block will be placed behind the cards and it and the cards will press against the load switch.
U.S. Pat. No. 5,431,399 (Kelley) describes a bridge hand-forming device in which cards are placed into an infeed area and the cards are randomly or predeterminately distributed to four receiving trays. A weight is shown placed over the infeed cards.
In shufflers where there is a single stack of cards to be shuffled and the weight of the cards presses the lowermost cards into contact with card-moving elements such as pick-off rollers, friction contact plates, and the like, it has been suggested by the inventors that as the stack of cards diminishes and fewer cards are present to provide contact forces with the lowermost card-moving element, this failure of strong contact forces may be a cause for delivery failures in the last cards in a set of cards in the delivery chamber. It would be desirable to provide a mechanism that applies a force to gravity-fed cards to assure consistent feeding, yet have the capability of automatically retracting as to not interfere with card loading.